The invention relates to a transmission with a transmission input shaft and a transmission output shaft and two power paths between the transmission input shaft and a driving gear set with two planetary gear sets with four shafts that in the sequence of rotational speeds are referred to as the first, second, third and fourth shafts, wherein a first of said power paths has a first fixed gear ratio and a second power paths has a second fixed gear ratio, wherein the second fixed gear ratio is smaller than the first fixed gear ratio.
Furthermore the invention relates to a hybrid powertrain for an automotive vehicle comprising at least one internal-combustion engine and at least one electric machine
A transmission of the kind mentioned is known, for example, from EP 0 434 525 A1. In the conventional transmission, which has five gear-shifting elements, whose selective paired intervention causes various gear ratios between the transmission input shaft and the transmission output shaft, there realized six forward gears and one reverse gear.
The patent application DE 10 2010 028 026 of the applicant also discloses a hybrid powertrain with a combustion engine and several electric motors. This hybrid powertrain uses one gear train with sub-gears, each having a shiftable gear. The shiftable gears provided in the sub-gears are engaged—apart from a direct gear with coaxial input and output—each with exactly one sub-gear, such as a spur-gear pair or a planetary gear. An eight-gear auxiliary transmission with coaxial output would then require for the eight gears at least eight sub-gears in the form of eight spur-gear pairs.
It is therefore the technical task of the invention to reduce the required construction outlay for a hybrid powertrain of the above-mentioned type with a multiple-gear transmission and to propose a load-shiftable transmission with at least eight gears, which allows high overall nips with very advantageous gear steps.